toradex: Include env.h to permit reading the environment

Two files read from the environment but don't not include the correct
header. Update them.

Signed-off-by: Simon Glass <sjg@chromium.org>

board/toradex/colibri_imx7/colibri_imx7.c

@@ -4,6 +4,7 @@
  */
 
 #include <cpu_func.h>
+#include <env.h>
 #include <init.h>
 #include <net.h>
 #include <asm/arch/clock.h>

board/toradex/verdin-imx8mm/verdin-imx8mm.c

@@ -3,7 +3,7 @@
  * Copyright 2020-2021 Toradex
  */
 
-#include <config.h>
+#include <env.h>
 #include <init.h>
 #include <asm/arch/clock.h>
 #include <asm/arch/sys_proto.h>